1. Field of the Invention
This invention relates to oven cleaning devices and in particular to means for effectively locking the oven door latching mechanism during a high temperature pyrolytic cleaning operation.
2. Description of the Background Art
In one known form of latching mechanism for use in controlling the opening of a door to a self-cleaning oven, a locking device is provided for maintaining the door latch in the latching condition whenever the temperature of the oven is above a preselected temperature, such as occurs during the self-cleaning operation. In one illustrative form of such mechanism, an operating handle is provided which extends outwardly for manipulation by the user. The operating handle normally provides means for controlling the latched condition of the oven door. The locking means is associated with the latching mechanism so as to prevent manipulation of the handle under such high temperature conditions.
One illustrative example of such a latching mechanism is shown in U.S. Pat. No. 3,438,666 of Karl H. Erickson. As illustrated in the Erickson patent, the locking means includes a blocking member rotated into and out of blocking relation with the latch under the control of a bimetallic heat sensing coil. The coil is separated from the oven wall insulation by a shroud arranged to cause the lower side of the coil to be exposed directly to the heat in the oven chamber. Thus, the coil is subject to fumes and gases generated during the cleaning operation.
Another U.S. Letters Patent showing a combination mechanical-thermal latch mechanism for use in a range oven is that of Carl. L. Anderson, U.S. Pat. No. 3,406,677. The Anderson structure is similar to that of the Erickson structure in the provision of a hole in the oven top subjacent the bimetal sensor element, permitting the sensor element to be subjected to the fumes and gases of the oven cavity in order to provide the desired sensing of the oven temperature.
Charles S. Mertler shows in U.S. Pat. No. 3,416,515 another form of door latching actuator assembly for use in controlling the opening of the door as during a high temperature self-cleaning operation of the oven. The temperature responsive mechanism of the Mertler patent includes a cylinderical housing having a bimetallic snap-acting disc disposed adjacent a lowermost end wall. The disc is retained in the housing by a ring or clips which are spot-welded to the housing.
Still another form of thermostatic mechanism for use in an electric range is shown in U.S. Pat. No. 2,265,026 of Earl K. Clark. The Clark thermostat includes a temperature compensator for independently adjusting the thermostat to maintain the oven temperature constant.